Consider the following kinds of organisms: 1) Bacteria 2) Fungi 3) Flowering Plants Some species of which of the above kinds of organisms are employed as biopesticides?

The answer is D, because all three groups supply biopesticides. Biopesticides are pest control agents derived from living organisms or their natural products, and they are a core part of Integrated Pest Management.

• 1) Bacteria: Correct. Bacillus thuringiensis (Bt) produces crystal proteins toxic to specific insect larvae, especially caterpillars, and Bt formulations are widely sprayed.
• 2) Fungi: Correct. Trichoderma species are used against soil-borne pathogens like Pythium and Fusarium, and Beauveria bassiana is used against sucking and chewing insects.
• 3) Flowering plants: Correct. Neem (Azadirachta indica) is an angiosperm whose extracts, rich in azadirachtin, act as antifeedants and growth regulators. Pyrethrum from Chrysanthemum cinerariifolium is another plant-based insecticide.

Mains link: biopesticides matter for GS-III questions on sustainable agriculture, pesticide residues in food, and soil and biodiversity health.

Trap: Many aspirants assume biopesticides are only microbial, or that plant-derived products do not count, and so pick B or C. Neem is the example to remember.